Exploration on Reducing Chemical Fertilizer Application in Baby Chinese Cabbage Cultivation

Abstract: Baby Chinese cabbage is a major variety of autumn vegetables in plain areas. In order to explore the reduction of chemical fertilizer application and reasonable formulas, improve the quality of baby Chinese cabbage and achieve zero growth of chemical fertilizers, a comparison was made between the application of organic fertilizers combined with special vegetable fertilizers and the traditional fertilization habits of farmers. Significant effects of increasing production and income were obtained, and an optimized fertilization scheme was explored for the high-yield and high-quality cultivation of baby Chinese cabbage.
Keywords: Baby Chinese Cabbage; Fertilizer Reduction; Formula

1.Demonstration and Comparison Setup

1.1 Soil Overview

The demonstration and comparison field was selected in the vegetable field of He Weiran in Group 1, Sanzhou Village, Wangji Town, Yicheng City. The soil type is fluvo-aquic soil. Its nutrient contents are available nitrogen 75mg/kg, available phosphorus 32.1mg/kg, available potassium 172mg/kg, organic matter 23.4g/kg, and the pH value is 6.8. The previous crop was corn.
1.2 Demonstration and Comparison Desig

Three treatments with four replicates were set up in the demonstration and comparison, and the area of each plot was 100m², arranged randomly. That is, the combination of organic fertilizers and special vegetable fertilizers was compared with two conventional fertilization schemes of farmers. The tested variety was Huangxinhuang produced in South Korea, provided by Beijing Fengqiao International Seed Co., Ltd. The planting density was 0.25m×0.25m, with 10,600 plants per mu. The same amount of 1,000kg of farmyard manure was applied per mu, and other cultivation and management measures were exactly the same. It was directly sown on September 16, 2017, and harvested on January 15, 2018.

1.3 Fertilizer Formulas

Scheme 1: Provided by Hubei "Yishizhuang" Agricultural Technology Co., Ltd., 50kg of 6% organic fertilizer (3-1-2:45) was applied per mu, and 100kg of 35% special vegetable fertilizer (18-5-12) was applied in combination [1].

Scheme 2: 50kg of 48% (18-15-15) Wuliangguan compound fertilizer produced by Guizhou Kailin Group Co., Ltd., and 50kg of 39% ammonium nitrate phosphate (26-13-0) compound fertilizer produced by Hubei Yingcheng Xindu Chemical Co., Ltd.

Scheme 3: 50kg of 51% Yangfeng compound fertilizer (25-10-16) produced by Hubei Yangfeng Fertilizer Co., Ltd., plus 70kg of ammonium bicarbonate and 6kg of urea; all were applied as base fertilizers in the furrow at one time and covered with soil. The design indicators of each scheme are shown in Table 1 (taking Scheme 1 as the control).

2.Results and Analysis of the Demonstration and Comparison

The demonstration and comparison were harvested by treatment, and the comprehensive yield of the four replicates was calculated according to the average value. The real-time selling price was 0.60 yuan/kg. The yield and benefits are shown in Table 2.

2.1 Obvious Effects of Increasing Production and Income
The combination of organic fertilizers and special vegetable fertilizers increased the yield by 488.3kg/mu compared with Scheme 2 of farmers' conventional fertilization, with a yield increase of 11.4%, and the net income of farmers increased by 292.90 yuan/mu, with an income increase of 15.9%. Compared with Scheme 3, the yield increased by 224.1kg/mu, with a yield increase of 4.9%, and the net income of farmers increased by 134.40 yuan, with an income increase of 7.3%.

2.2 The Combination of Special Vegetable Fertilizers and Organic Fertilizers Promotes Yield Increase

Special vegetable fertilizers are formulated based on the growth characteristics and nutrient requirements of vegetables, which have been verified through practice and are significantly better than general-purpose fertilizers. Increasing the application of organic fertilizers can promote the decomposition and reuse of residual nutrients in the soil and improve the utilization rate of fertilizers [2]. Although the amount of applied nutrients is reduced, a better harvest can be obtained with less input of fertilizer nutrients.

2.3 Principles to be Followed for Reducing Chemical Fertilizer Application

The phenomenon of blind fertilization in vegetable production is prominent. There is an excessive emphasis on nitrogen (N) and phosphorus (P), a neglect of potassium (K), and a disregard for medium and trace elements. There is also a superstition about chemical fertilizers and a 轻视 of organic fertilizers, which has led to a deterioration in the quality of cultivated land and low production-to-input benefits for farmers. The demonstration and comparison have verified the feasibility of reducing chemical fertilizers. Compared with conventional fertilization, the combination of organic fertilizers and special vegetable fertilizers for baby Chinese cabbage still increased the yield by more than 4.9% even when the application of pure nutrients per mu was reduced by 2.2-5.5kg, with a reduction range of 5.8%—14.5%, which is sufficient to prove that the conventional fertilization scheme is not reasonable enough. The principles to be followed for reducing chemical fertilizers are: reduce the amount of blindly applied fertilizers, the amount of nutrients redundant for crop growth, and the amount that can be replaced by applied organic fertilizers; the reduction must be carried out through field experiments and demonstrations to understand the laws, obtain data, and put forward guiding suggestions; random reduction will inevitably lead to a decrease in yield.

3.Conclusions and Suggestions

3.1 The combination of organic fertilizers and special vegetable fertilizers is the best choice for baby Chinese cabbage production. It can not only improve the physical and chemical properties of the soil, maintain the balance of soil nutrients, and improve the utilization rate of nutrients, but also save resources and promote the increase of agricultural production and income [3], which is worthy of in-depth research, multiple-point demonstrations, and extensive promotion.

3.2 Reducing the conventional fertilization of vegetables by 10% can increase the yield (with a reasonable formula). In the demonstration and comparison, the conventional fertilization applied 2.5-7.7kg more pure nitrogen, Scheme 2 applied 8.5kg more pure phosphorus, and Schemes 2 and 3 had 5-5.5kg less pure potassium. Due to the unreasonable nutrient ratio and the lack of knowledge of the law that crops form yields with the minimum nutrients, the redundant nutrients were wasted, resulting in low yields and poor benefits. Practice has proved that an appropriate fertilizer formula is the key to cost reduction and income increase, the combination of organic and inorganic fertilizers is the focus of the sustainable development of agriculture, and reducing fertilizers and pesticides is the direction of the development of ecological agriculture.

3.3 Fertilization Suggestions. Based on the fertilizer requirements of baby Chinese cabbage, drawing on the fertilization experience of farmers' habits, and referring to the results of multiple-point demonstration and comparison in the field, when the yield per mu of vegetables reaches more than 5,000kg, it is recommended to apply the "Yishizhuang" series of fertilizers. The schemes are as follows [4]: ① 50kg of 15% bio-organic fertilizer (9-2-4:25) + 90-100kg of 35% (18-5-12) special vegetable fertilizer; ② 50-80kg of 6% organic fertilizer (3-1-2:45) + 90-100kg of 35% (18-5-12) special vegetable fertilizer; ③ 90-100kg of 40% potassium sulfate type (16-8-16) special fertilizer; ④ 130-140kg of 30% (15-6-9:15) organic-inorganic special vegetable fertilizer; Select the appropriate fertilizer formula and application amount according to the soil type and nutrient content to achieve the reduction of chemical fertilizers, the increase of vegetable yields, the improvement of quality, and the increase of farmers' income.

References:

[1] Zhao Yitao. Soil and Fertilizer Science [M]. Beijing: China Chemical Industry Press, 2009.

[2] Zhang Zhenxian. Vegetable Cultivation [M]. Beijing: China Agriculture Press, 2003.

[3] Gao Xiangzhao. Practical Handbook of Fertilizers [M]. Beijing: China Agriculture Press, 2002.

[4] Wang Xiaoxue. Reasonable Fertilization of Vegetables [M]. Beijing: China Agriculture Press, 1997